from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The outer layer of a blastula that gives rise to the ectoderm after gastrulation.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. the outer layer of a blastula that, after gastrulation, becomes the ectoderm
from the GNU version of the Collaborative International Dictionary of English
- n. The outer layer of the blastoderm; the ectoderm. See blastoderm, delamination.
from The Century Dictionary and Cyclopedia
- n. In botany, a name applied by Richard to a second small cotyledon which is found in wheat and some other grasses.
- n. In embryology, the outer or external blastodermic membrane or layer of cells, forming the ectoderm or epiderm: distinguished at first from hypoblast, then from both hypoblast and mesoblast. See cut under blastocæle.
It has long been known that certain cells of an early mammalian embryo—known as epiblast cells—can naturally become primordial germ cells, which, in turn, give rise to sperm or eggs.
It has long been known that certain cells of an early mammalian embryo -- known as epiblast cells -- can naturally become primordial germ cells, which, in turn, give rise to sperm or eggs.
During mouse embryo development, the blastocyst differentiates into pluripotent primitive ectoderm and gives rise to a structure known as the epiblast
Ectoblast: the outer wall of a cell; the ectoderm or epiblast.
It is based upon the fact that the histological differentiation of the epidermis of their root is that generally characteristic of Monocotyledons, whilst they have two cotyledons -- the old view of the epiblast as a second cotyledon in Gramineae being adopted.
The remainder of the epiblast constitutes the epidermis.
From the epiblast the epidermis (not the dermis), the nervous system
The outer layer of this double-walled sac is called the epiblast.
A mammalian tooth has essentially the same structure: an outer coat of enamel, derived from epiblast, overlies a mass of dentine, resting on bone, but the dentine is excavated internally, to form a pulpcavity containing blood-vessels and nerves.
The neural folds ultimately bend over and meet above, so that s.c. becomes a canal, and is finally separated from the epiblast to form the spinal cord.